See also: http://arxiv.org/abs/1203.2512
Ancient bronze disks, decorations and calendars, Amelia Carolina Sparavigna
(12 Mar 2012) Recently, it was published that some ancient bronze disks could had been calendars, that is, that their decorations had this function. Here I am discussing an example, the disk of the Trundholm Sun Chariot, proposing a new interpretation of it, giving a calendar of 360 days. Some geometric diagrams concerning the decoration layout are also proposed. Comments: Ancient calendars, ancient time-keeping, Bronze Age, Trundholm Sun Chariot
Cite as: arXiv:1203.2512 [physics.pop-ph]

See also http://arxiv.org/abs/1203.4103
Number pi from the decoration of the Langstrup plate, Amelia Carolina Sparavigna
(19 Mar 2012), Studies of ancient bronze artifacts can be useful in understanding the progression of human knowledge of mathematics and geometry. Here I discuss the decoration composed by several circles and spirals of the Langstrup belt disk, an artifact of the Bronze Age found in Denmark. I am showing by measurements of diameters and distances of spirals, that the artist who made the decoration knew some approximations by rational numbers of the number pi, the dimensionless physical quantity representing the ratio of circumference to diameter. Comments: Ancient measurements of pi as ratio of circumference and diameters, giving rational numbers,
Cite as: arXiv:1203.4103 [physics.pop-ph]